ABSTRACT: Transcription profiling by array of maize plants infected with Ustilago maydis mutant for cluster 19A and individual subdeletions for genes tin1, tin3, tin4 and tin5
Project description:Many of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. Many of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We used the Affymetrix maize genome array to analyze the transcriptional responses of maize to cluster 19A mutants and individual sub-deletions for the cluster 19A genes tin1, tin3, tin4 and tin5. We found plant responses to the mutants were significantly different although the macroscopic phenotypes of the individual mutants were very similar.
Project description:Many of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. Many of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We used the Affymetrix maize genome array to analyze the transcriptional responses of maize to cluster 19A mutants and individual sub-deletions for the cluster 19A genes tin1, tin3, tin4 and tin5. We found plant responses to the mutants were significantly different although the macroscopic phenotypes of the individual mutants were very similar. U. maydis infected parts of maize seedling leaves were dissected 4 days after inoculation with strain SG200∆19A, SG200∆tin1, SG200∆tin3, SG200∆tin4 and SG200∆tin5, respectively. We previously submitted data of maize leaves that were treated with the progenitor wild type strain SG200 as well as mock-infections under identical experimetal conditions (GEO: GSE10023). These data served as controls for this experiment.
Project description:Transcription profiling by array of Bacillus amyloliquefaciens strain FZB42 after interaction exudates (IE) treatment, at OD600=1.0 and at OD600=1.0 respectively. IE was the root exudates prepared from maize plants growing with FZB42. The reference was treated with the root exudates (RE), prepared from maize plants grown in an axenic system.
Project description:Anthocyanin induction in plant is considered a general defense response against biotic and abiotic stresses. The infection by Ustilago maydis, the corn smut pathogen, is accompanied with anthocyanin induction in leaf tissue. We revealed that anthocyanin is intentionally induced by the virulence promoting secreted effector protein Tin2. Tin2 protein functions inside plant cells where it interacts with cytoplasmic maize protein kinase ZmTTK1. Tin2 masks an ubiquitin-proteasome degradation motif in ZmTTK1 leading to a more stable active kinase. Active ZmTTK1 controls transcriptional activation of genes in the anthocyanin biosynthesis pathway rerouting phenylalanine away from lignin biosynthesis. Therefore, we performed microarray analysis to understand how maize gene transcription in phenylpropanoid pathway is differentially changed after infection with Ustilago maydis SG200 (wild type) and SG200Dtin2 (anthocyanin-inducing effector mutant). We prepared three biological replicates for mock-inoculated maize (control), SG200-infected maize and SG200M-NM-^Ttin2-infected maize. For 1 sample, we harvested the leaves (1-3cm below injection hole) from 20 plants and pooled them. At 4 days post inoculation, total RNA was extracted.
Project description:We report the application of single-molecule-based sequencing technology for high-throughput profiling of transcriptome in mazie plants. The ZmPIS gene coding PtdIns synthase from maize with a maize ubiquitin promoter was transferred into maize. The transgenic ZmPIS maize showed enhanced drought tolerance compared to non-transgenic maize. The differentially expressed genes between wide-type maize and transgenic ZmPIS maize were detected by the assay of digital gene expression profile and real time RT-PCR datas. The results displayed that the overexpression of ZmPIS resulted in the expression levels changes of a large number of genes including genes involved in the phosphatidylinositol (PI) metabolic pathway, photosynthesis metabolism, carbohydrate metabolism, aminoacid metabolism and genes coding transcription factors.
Project description:DNA methylation is a chromatin modification that is sometimes associated with epigenetic regulation of gene expression. As DNA methylation can be reversible at some loci, it is possible that methylation patterns may change within an organism that is subjected to environmental stress. In order to assess the effects of abiotic stress on DNA methylation patterns in maize (Zea mays), we subjected seedlings to heat, cold and UV stress treatments. Tissue was later collected from individual adult plants that had been subjected to stress or control treatments and used to perform DNA methylation profiling to determine whether there were consistent changes in DNA methylation triggered by specific stress treatments. The DNA methylation profiling was performed by immunoprecipitation of methylated DNA followed by microarray hybridization to allow for quantitative estimates of DNA methylation abundance throughout the low-copy portion of the maize genome. By comparing the DNA methylation profiles of each individual plant to the average of the control plants it was possible to identify regions of the genome with variable DNA methylation. However, we did not find evidence of consistent DNA methylation changes resulting from the stress treatments used in this study. Instead, the data suggest that there is a low-rate of stochastic variation that is present in both control and stressed plants. Methylation profiles in flag leaf tissue of maize inbred lines under various stress conditions using a custom 1.4M feature NimbleGen array.
Project description:Background: Maize plants developed typical gray leaf spot disease (GLS) symptoms initiating at the lower leaves and progressing to upper leaves through the season. Leaf material was collected at 77 days after planting, at which stage there were a large number of GLS disease necrotic lesions on lower leaves (8% surface area on average determined by digital image analysis), but very few lesions and only at chlorotic stage on leaves above the ear (average of 0.2% lesion surface area). Method:To collect material that reflected a difference between C.zeina infected B73 leaves and control B73 leaf material, samples were collected from two lower GLS infected leaves (second and third leaf internode below ear) , and two upper leaves with minimal GLS symptoms (second and third internode above ear), respectively. The two lower leaves from each plant were pooled prior to RNA extraction, and the two upper leaves from each plant were pooled prior to RNA extraction. Upper and lower leaf samples from three maize B73 plants were subjected to RNA sequencing individually. The three maize plants were selected randomly as one plant per row from three rows of ten B73 plants each. Result: A systems genetics strategy revealed regions on the maize genome underlying co-expression of genes in susceptible and resistance responses, including a set of 100 genes common to the susceptible response of sub-tropical and temperate maize.
Project description:DNA methylation is a chromatin modification that is sometimes associated with epigenetic regulation of gene expression. As DNA methylation can be reversible at some loci, it is possible that methylation patterns may change within an organism that is subjected to environmental stress. In order to assess the effects of abiotic stress on DNA methylation patterns in maize (Zea mays), we subjected seedlings to heat, cold and UV stress treatments. Tissue was later collected from individual adult plants that had been subjected to stress or control treatments and used to perform DNA methylation profiling to determine whether there were consistent changes in DNA methylation triggered by specific stress treatments. The DNA methylation profiling was performed by immunoprecipitation of methylated DNA followed by microarray hybridization to allow for quantitative estimates of DNA methylation abundance throughout the low-copy portion of the maize genome. By comparing the DNA methylation profiles of each individual plant to the average of the control plants it was possible to identify regions of the genome with variable DNA methylation. However, we did not find evidence of consistent DNA methylation changes resulting from the stress treatments used in this study. Instead, the data suggest that there is a low-rate of stochastic variation that is present in both control and stressed plants. Methylation profiles in flag leaf tissue of maize inbred lines under various stress conditions using a custom 1.4M feature NimbleGen array. Methylation profiles of flag leaf tissue from 18 B73 inbred lines that underwent various stresses as seedlings. This includes 5 cold treatment plants, 4 UV treated plants, 3 heat treated plants, and 6 total control plants (no stress). All methylation profiling was done on a custon 3x1.4M NimbleGen array platform (meDIP-chip).
Project description:Studies investigating crop resistance to biotic and abiotic stress have largely focused on plant responses to singular forms of stress and individual biochemical pathways that only partially represent stress responses. Thus, combined biotic and abiotic stress treatments and the global assessment of their elicited metabolic expression remains largely unexplored. In this study, we employed targeted and untargeted metabolomics to investigate the metabolic responses of maize (Zea mays) to both individual and combinatorial stress treatments using heat (abiotic) and Cochliobolus heterostrophus infection (biotic) experiments. Ultra-high-performance liquid chromatography-high-resolution mass spectrometry revealed significant metabolic responses to C. heterostrophus infection and heat stress, and comparative analyses between these individual forms of stress demonstrated differential elicitation between the two global metabolomes. In combinatorial experiments, treatment with heat stress prior to fungal inoculation negatively impacted maize disease resistance against C. heterostrophus, and distinct metabolome separation between combinatorial stressed plants and the non-heat stressed infected controls was observed. Targeted analysis revealed inducible primary and secondary metabolite responses to biotic/abiotic stress, and combinatorial experiments indicated that deficiency in the hydroxycinnamic acid, p-coumaric acid, may lead to the heat-induced susceptibility of maize to C. heterostrophus. Collectively, these findings demonstrate that abiotic stress can predispose crops to more severe disease symptoms, underlining the increasing need to investigate defense chemistry in plants under combinatorial stress.
Project description:The expression profiling of a newly identified maize dwarf mutant Dwarf11 (D11) was investigated by Affymetrix array. Results showed that transcripts encoding GA biosynthetic and catabolic enzymes ent-kaurenoic acid oxidase (KAO), GA 20-oxidase (GA20ox), and GA 2-oxidase (GA2ox) were up-regulated in the D11 mutant. We used microarrays to identify the difference of GA-related gene expression in D11 mutant.